This invention relates to lighting and/or signalling apparatus for a motor vehicle, and in particular to motor vehicle headlights.
1. Field of the Invention
More particularly, it relates to light beams for lighting to the side of the vehicle. This should be understood to mean light beams which give lighting in a general or mean orientation which is oblique with respect to the longitudinal axis X of the vehicle (this axis being generally collinear with, or little different from, the orientation of the optical axis of the other beams, or so-called main beams, emitted by the headlights).
2. Description of the Related Art
In the sense of the invention, and without any limitation, the light beams may be emitted by optical modules in order to provide, on bends, complementary lighting on the side into which the vehicle is turning. This function is called a “fixed bend light” function (FBL). It is for example described in patent No. EP 864 462. The FBL beam is accordingly associated with a standard beam of low beam type emitted by an optical module called the main module, so as to give a general beam having a wider angular aperture, the general beam being required to conform with a photometric grid which is defined in the current regulations for the functions known as advanced front lighting systems (AFS).
The invention may also relate to light beams which provide a lighting function of the kind known as “cornering”, that is to say lighting on corners, the object of which consists in giving improved lighting to the side of the vehicle, not only in order to give the driver of the vehicle better visibility (the lighting function), but also to enable the vehicle itself to be discerned better from its surroundings (the indicating or signalling function). This function is, for itself alone, defined by a specific photometric grid which is provided in the current regulations.
The common point of these two types of beams, “cornering” and complementary FBL, is that it is necessary to achieve a sufficient supply of light along an axis which is oblique with respect to the longitudinal axis of the vehicle, which poses a certain number of problems, because headlights usually comprise one or several optical modules emitting light beams the optical axis of which is more or less coincident with the longitudinal axis of the vehicle. (An “optical module” is to be understood to mean an assembly of components which comprises at least one reflector, with its associated light source or sources and, if applicable, associated optical elements such as dioptric elements, Fresnel lenses and so on, adapted to emit at least one given light beam).
A first solution consisted in turning, inside the headlight, the module which is adapted to light up towards the side with respect to the other optical modules: the headlight retains its usual configuration, with its main modules, for example the one emitting the low beam or the high beam, while the complementary FBL or “cornering” module is turned in such a way that its optical axis makes an angle with the optical axis of the other modules.
This solution does however have its limits; a module turned in this way takes up more space inside the headlight in which, in particular, lamp connecters are disposed obliquely and the reflector occupies more space. Compactness is now being demanded more and more in a headlight. In addition, to turn a module in this way does tend to involve a loss of light flux emitted by the module: the most oblique rays tend not to be able to emerge from the cover lens of the headlight. Therefore, following the form of the headlight, the amplitude of rotation of the module is accordingly limited to a greater or lesser extent, and it is difficult to guarantee that the beam emitted by the module and effectively leaving the headlight is fully compatible with the current regulations.
There is, therefore, a need to overcome one or more problems of the prior art by providing an improved lighting and/or signalling apparatus.